Aperture card system



Jan. 19, 1965 J. F. LANGAN vAPERTURE CARD SYSTEM 3 Sheets-Sheet 1 FiledNov. 21, 1960 nnnongn a na nn FlC3.2.

' INVENTOR dorm F. LANGAN Jan. 19, 1965 Filed Nov. 21, 1960 J. F. LANGANAPEIRTURE CARD SYSTEM 3 Sheets-Sheet 2 PREQSURE I 37 FIG. 11. 1

1,41 41* 1 36 as 9 40 a9 1 L V/ l 11 \1 H F i OSCILLATOR 2 INVENTOR JOHNF. LANGAN ATTORNEYS Jain. 19, 1965 .1. F. LANGAN 3,165,848

APERTURE CARD SYSTEM Filed Nov. 21, 1960 3 Sheets-Sheet 3 Riki 15 FIG.10

INVENTOR JOHN P. LAN GAN ATTORNEYS United States Patent 3,165,848APERTURE CARD SYSTEM John F. Langan, Atlanta, Ga., assignor to LanganAperture Cards, Inc., New York, N.Y., a corporation of Delaware FiledNov. 21, 1960, Ser. No. 70,814 2 Claims. (Cl. 49-158) This inventionrelates to improvements in mounting transparencies such as individualmicrofilm sections in film record cards to facilitate the handling,filing and storage of the transparencies, and also the sorting out,projecting and if desired reproducing individual transparencies whendesired.

The invention is particularly useful in mounting microfilm sections incards that are capable of being sorted mechanically, although it is notlimited to this use as explained hereinafter. Various types ofmechanical sorting systems are well known. The range from systems inwhich groups of related cards can be separated and extracted from astack by inserting a pin or the like through aligned holes in the edgesof the cards, to the elaborate and well known IBM system in which thecards are perforated according to a code and are sorted by electricallycontrolled apparatus responsive to the location of the perforations inthe individual cards. However, the invention also comprehends themounting of projectionable transparencies, including all types ofphotographic film records, in ordinary file cards, catalog cards, andthe like.

With reference to machine sorting of the IBM type, the present inventioncomprises improvements of the punch cards or aperture cards disclosed inmy prior Patents Nos. 2,511,859, 2,512,106, and 2,587,022, as well as inthe preparation and use of such cards. Aperture cards of the type shownin these prior patents have been very widely used, especially by theUnited States Government. By way of example, a current program ofstandardization of the preparation and distribution of engineering databy this system, such as drawings, specifications and the like, in oneparticular Government field is estimated to require 90 million aperturecards initially and average annual usage thereafter of 15 millionaperture cards.

The merit of such aperture card systems is attested by their widespreadadoption and successful use, in spite of serious defects of priorsystems which are corrected by the present invention. One such defecthas had to do with the blank cards as supplied in bulk quantity to theultimate user, i.e., before the film is mounted therein. As disclosed inmy prior Patent No. 2,511,859 mentioned above, these blank cards aresupplied already apertured with a strip of adhesive material secured tothe backside of the card around the edges of the aperture, a narrowsection of this strip extending into the aperture with exposed adhesivethereon for subsequent mounting of a transparency in the aperture. Thisexposed adhesive is covered by a temporary sheet of glassine paper orsimilar material.

In the first place, such blank cards cannot ordinarily be furnished to aprospective user in large supply because they must be used within arelatively short period or else the adhesive deteriorates to the pointwhere adequate bonding of the transparency cannot be secured. In largepart because of this inability to store reserve supplies of blank cards,the common practice has been for the customer to send his microfilm to acentral service center where the individual film sections are mounted inthe cards. The fact that the customer cannot cut out and mount sectionshimself, as and when desired, has made for inflexibility in the use ofprior aperture card systems and has detracted seriously from theirutility and desirability.

The factor mentioned above also makes it practically impossible to useaperture cards for mounting two or more sequential transparencies on thesame card, as is often 3,165,848 Patented Jan. 19,, 1965 ice desirablein order to post a record of successive stages of development of aproject. In such cases, it is desirable to mount the first transparencyin one aperture of a card, and to be able to supplement the originalrecord by mounting a second transparency at some later date in a secondaperture of the same card. When the time came for mounting the secondtransparency, however, the adhesive material around the second aperturewould no longer be efiective so that a separate card would have to beused.

Another problem arises from frequent sticking together of adjacent cardsdue either to exposed adhesive in the case of imperfect preparation, orto bleeding of the adhesive material from underneath the edges of theprotective glassine cover sheet or the edges of the transparency itself.In such cases the separation of blank cards for perforation according toa mechanical sorting code, or for the operations of mounting sections offilm therein, or during subsequent use of the finished cards for machinesorting, projection, and the like, is hindered to an extent whichmilitates seriously against the usefulness of such systems.

Furthermore, any increase in thickness of such cards is veryundesirable. Even though an applied strip of adhesive may only increasethe thickness of a card by an extremely small amount, say 1/1000th of aninch, still when a deck of 1000 or more cards are stacked in a filedrawer as is often the case, there will be a difference of an inch ormore in the length of one side of the stack as compared with the other.

Still further objections to prior systems arise from the fact that theoperations involved in preparing the blank cards, i.e., punching out theapertures and then applying the adhesive strips and the cover sheets, aswell as the operations involved in finishing the cards includingstripping off the cover sheets and disposing of them and then applyingthe transparencies to the exposed adhesive strips, both requireobjectionably elaborate and expensive apparatus such as illustrated forexample in the prior Standish Patent No. 2,666,543, the prior MorrisonPatents Nos. 2,493,159 and 2,560,301, and the prior Baker Patent No.2,643,786. Many users of aperture cards have only a relatively smallnumber of transparencies to be mounted at one time, and this onlysporadically, so that they cannot justify the expense of purchasing andmaintaining such elaborate equipment but must again rely on servicecenters such as mentioned above.

But perhaps a more basic objection is that the bond between thetransparency and the card is not secure enough in many cases. Forexample, under ordinary conditions of usage, a deck comprising say 1000cards bearing microfilmed engineering drawings must last for yearsdespite repeated handling incident to removing the cards from andreturning them to the drawer, riffiing decks of cards before placingthem in sorting machines, handling individual cards in projectionmachines, print copiers, and the like, etc. In the course of suchmanipulations, the cards are repeatedly subjected to twisting andbending from all possible angles. Unless the bond between the filmsection and the card is continuous, strong, and permanent, separation ofthe film from the adhesive may eventually occur with the result that thecard must be thrown away and the film section remounted in a fresh blankcard.

Added to the above disadvantages is the fact that even though theaperture in the blank card is covered by a temporary removable coversheet, still the presence of the aperture is undesirable for variousreasons. It ob viously detracts from the mechanical strength of theblank card, and it may interfere with and hinder the perforation of thecard for mechanical sorting before the transparency is mounted.

Various attempts of course have been made to eliminate the use ofadhesives and to remedy the defects mentioned, but none have beensuccessful. Among such attempts, by way of example, is my prior latentNo. 2,587,022 in which heat bondin of thermoplastic materials to thecard was suggested. For example, it was proposed to cover the aperturewith a sheet of cellulose acetate and to bond its edges by heat andpressure to the edges of the card around the aperture. Since this coversheet would be of the same material as the base of the film itself, itwas thought that the film section and the cover sheet could be unitedintegrally by heat to form a unitary transparency across the aperture.Usually heat damage resulted, such as clouding and/or buckling orwarping of the film. Moreover, the bond formed by heating the celluloseacetate cover sheet in contact with the card, or the cellulose acetatebase of the film itself as suggested in my Patent No. 2,633,655, wasunsuccessful. If the degree of heat was only enough to soften thecellulose acetate it would not penetrate the fibers of the card and thebond was weak. ttempts to increase fluidity by raising the temperatureusually caused warping or buckling of the card itself.

One of the objects of the present invention is to provide an improvedaperture card system which not only eliminates adhesives but alsoprovides a stronger and more permanent bond between the transparency andthe card in which it is mounted.

Another object is to provide such an improved aperture card system whichis simpler to use and requires substantially less elaborate and costlyequipment, but which also remedies the defects of prior syst ms asoutlined above and at the same time provides greater flexibility andadaptability in use.

More particularly, it is an object of the invention to provide animproved aperture card system utilizing a blank card which is bothcontinuous in extent (i.e., not apertured) and uniform in thicknessthroughout its entire area, and is characterized by the complete absenceof surface stickiness, being to all intents and purposes the same as theblank cards heretofore used in non-aperture card systems in whichtransparencies are not mounted in the cards.

Another object is to provide a novel aperture card as characterized inthe preceding object, and further a blank card of this type in whichthere is no material deterioration over prolonged periods of storage,thereby facilitating the supply of blank cards in bulk quantities foruse when needed, enabling the consecutive posting at intervals of filmrecords and the like on the same card, etc.

A further object is the provision of a novel blank record card ascharacterized above, and a novel quick, easy and inexpensive procedurefor making it, whereby thermoplastic bonding material is impregnatedinto and beneath the surface of the fibrous card material at desiredpoints and carried permanently thereby ready for use when needed,without material change in the exterior of the card.

It is still another object of the present invention to provide animproved aperture card system utilizing an improved method of mountingtransparencies in the blank aperture cards as characterized in thepreceding objects, which method is relatively simple to practice andrequires the use only of simple inexpensive equipment within the reachof any substantial user of the system, so that with a reserve supply ofblank cards, transparencies can be mounted as and when desired and ifdesired only a few at a time by the user or customer himself.

Further objects thus are to eliminate the need for relying on servicecenters of the type described above, and to enable the transparencies tobe prepared and mounted on the spot by the user who is familiar bothwith the transparencies and their significance and with the conditionsof use of the mounted transparencies.

Another object is to provide an improved method as characterized in thepreceding objects which produces a stronger and more permanent bondbetween the transparency and the card.

Yet another object is to produce a thermally activated fusion or bondbetween the impregnating material and the material of the transparencyitself, and at the same time to control the heating operation so as toavoid damage to the portion of the transparency that is to be projected.

Still further objects include the provision of an improved aperture cardsystem in which the transparency is mounted in the card Without the useof adhesives that are likely to cause sticldng; in which thetransparency is mounted in the card without appreciably increasing thethickness of the card; in which the bond between the transparency andthe card is not only much stronger than in prior systems, butsubstantially as strong and practically as durable as the card itself;and in which the thermoplastic material of the edges of the transparencyitself is fused integrally with a like or a comparable materialimpregnated into the card so as to form a substantially homogeneous bodyof material integral with the transparency around its edges in which thecard fibers at the edges of the apertures are embedded.

Generally speaking, the card may be of any suitable size and shapeaccording to the use to which it is to be put, and it may be desired tomount one or a plurality of transparencies at selected locations. Thefirst operation in the present invention is to impregnate the cardmaterial or at least the surface layer thereof where the film is to bebonded thereto, with a thermoplastic material capable of uniting orfusing with the material of the transparency itself when both are heatedsuificiently to become soft and flowable under light pressure. Theimpregnating material should be dry and non-sticky or nontacky atordinary temperatures, say up to 200 F. or higher for example, and hencethe use of temperatures high enough to liquify such materials involvesthe risk of damage to the card, while on the other hand the materialeven when melted lacks the fluidity required to penetrate the fibers.impregnation is accomplished by dissolving the impregnating material ina solvent at or near room temperature. In most modern films, the use ofcellulose nitrate as a film base has been abandoned in favor ofcellulose acetate, and hence the impregnating material is usuallyrequired to be compatible, i.e., fusible, with the cellulose acetateforming the film base. Cellulose acetate itself is the preferredimpregnating material in most cases. It can be dissolved, for example,in known solvents such as ethyl acetate, cyclohexanol, nitropropane,ethylene dichloride, and preferably in the readily available and widelyused dimethyl ketone or acetone.

The depth to which the card will be impregnated b neath its surface willdepend on factors such as the porosity of the fibrous material of thecar ditself, the viscosity and surface tension of the solution,capillarity, and of course on the amount of solution applied, and can becontrolled accordingly. However, it has been found that only the surfacelayer need be impregnated in order to insure a good bond, since thestrength of the bond appears to depend on uniting or fusing the materialof the film itself with preimpregnated material in which the surfacefibers of the card are embedded or secured. It may be desirable to colorthe solution, in which case after the solvent dries out, the zone ofimpregnation will remain colored.

The Zone of application of the solution must be such that theimpregnating material will be located around the edges of the aperture,when it is eventually cut out. Of course, this can be accomplished byapplying solution over the entire area of the aperture, but it is moreeconomical and just as effective to distribute the solution in a strippattern following the outline of the aperture. If a plurality ofapertures are contemplated, there will be a plurality of such outlinesto be followed. They may be marked on the cards or not, but at leasttheir locations will be predetermined and known. The solution can beapplied in the desired strip pattern or patterns by hand by simplybrushing it on the surface of the card, but usually suitable mecharu'calapplicator means will be preferred, For example, the cards may be movedin succession through a Zone of application in which the desired strippattern application is effected by relative movement between theindividual cards and suitable applicators. A reciprocable stampingdevice with a suitable inlrer can be used, or the cards may be fed insuccession through rotary printing devices; in either case the solution,colored or not, provides the ink with which the card is printed in thedesired pattern.

So printed and then allowed to dry, the cards are ready for sale in bulkas blank cards. Except where they are preferably colored in printing,they are outwardly exactly the same as the original cards, withoutstickiness, wi

out increase in thickness, and still of their original strength, butwith celluloseacetate impregnated into the fibrous material beneath thecard surface. Here it remains unchanged Without deterioration for aslong as may be desired until the aperture or apertures are eventuallycut; or in case a particular aperture is not cut out, as when a secondaperture outline is provided for posting but not used, the impregnatingmaterial simply remains in the card without in any way detracting fromits intended use.

When it comes to mounting a transparency in a blank card of the abovetype, the transparency is prepared in any suitable way. For example, itnay require edge trinimin to provide the desired size and shape, whichobviously can be done by hand if desired. In cutting out transparenciesfrom a roll of film or the like, however, suitable die-cuttingapparatus, either hand or power operated, will usually be preferred.

The same type of die-cutting operation is preferred for cutting out theapertures in the cards. With the aid of suitable registering means, thecards can be fed one by one to a die in position such that operation ofthe die cuts the aperture with its edges lying in the strip pattern ofimpregnant. Any desired type of feeding mechanism can be used, or thecards can be fed by land. For most purposes a simple reciprocating dieis satisfactory; it

can be operated by hand or, foot, or by power means.

The male die part may fit rather loosely in the female die part sothatthe cut edges of the aperture tend to be somewhat ragged rather thansmooth, as this effect 801 .etimes appears to improve the bon ingaction.

For bonding, the transparency is placed over the aperture with itsoverlapping the margins of the card around the aperture by a smallamount, say nd to th of an inch. in the case of photographic film, thebase side of the transparency, as distinguished from the side coatedwith the ligh -sensitive emulsion, is placed next to the card, usuallyon the back side of the card although it can be on the front side ifdesired. For convenience, the transparency is usually laid on the top ofthe card, Whichever side thereof may be upward. Bonding is thenaccomplished by a combination of heat and pressure, the zone of pressureapplication being restricted substantially to the overlapping areas oftie transparency and card. Where resistance heating is employed, theheating means are so arranged, as by means of heat-conductivedistributing plates, for example, that heat is restricted substantiallyto the marginal overlapping portions of the card and film. Electricalheating means such as coiled Nichrome wires may underlie the heatdistributing'plates and may be connected with suitable energizingcircuits capable of producing flash heating for short periods, usu allyonly a few seconds.

Although good results have been obtain-ed by resistance heating, it hasbee found more advantageous to use dielectric heating, especially in thecase of machine sorting where any degree of Warping or buckling of thecard is objectionable. It will be understood that with the rightfrequency, it may be possible to heat only the cellulose acetate impegnated into the card and on the film, without materially increasing thetemperature of the card fibers, and to attain a much higher temperatureof the cellulose acetate in a much shorter time. The conditions are notcritical, however. For example, using a 3,000 watt oscillator at afrequency of 27 megacycles, one or two seconds of heating weresufficient to produce a good bond without damaging the card, even whenonly about half of the available power was used,

Assuming the use of cellulose acetate solution for impregnation of thecard and a photographic film having a cellulose acetate base, thebonding action appears to be explainabe as follows, although it will beunderstood that the exact effects are microscopic in detail and somewhatobscure. lt appears that the cellulose acetate solution soaks into thecard to the desired depth, and that when the solvent evaporates, whichtakes place rapidly, the residual cellulose acetate is distributedthrough the impregnated zone of the card, presumably being deposited onthe individual fibers of the cardboard and at least partially fillingthe voids between these fibers. When heat is applied as described above,the impregnated cellulose acetate and the cellulose acetate base of thelm soften and become sernlliquid and thermoplastic to an extentdepending on the temperature attained. This may take place at temperatues in the range of 66 C.l00 C., although the melting point is muchhigher. With the concomitant application of pressure, the softenedcellulose base of the merges with the likewise softened celluloseacetate impregnated into the card and the total quantity of celluloseacetate hardens into a homogeneous integral body with the cardboardfibers embedded therein upon cooling. Excess softened cellulose acetatetends to squeeze out beyond the edge of the film section, or in aroundthe edges of the aperture, with consequent thinning of the overlappingmarginal portions of the film. At the same time there is a reduction inthickness of the marginal portions of the card itself due to the appliedpressure and heat, with the result that upon cooling, the combinedthickness of the overlapping edges or margins of the card around theaperture and edges or margins of the film is not materially greater thanthe original thickness of the card itself. The major portion of the areaof the transparencyQie, all of it except the narrow marginal strips,retains its original thickness and is depressed into the aperture, theincrease in thickness forming a sort of shoulder which abuts the edge ofthe card aperture. In some cases, as when the card has been deeplyimpregnated and the softened cellulose acetate of the film base issqueezed in between the abutting shoulder of the film and edge of theaperture, additional bonding may talre place, but this is not necessaryto produce a satisfactory product.

It will be understood that the entire bonding action taxes only a fewseconds, at the most, and that the thermoplastic material cools and setsvery rapidly, so that the entire operation of mounting the transparencyin the card with a strong permanent bond is very quickly and simplyaccomplished. In large part, the effectiveness of the bonding actionappears clearly to be due to the presence in the fibers of the cardaround the aperture of the impregnating body of the cellulose acetate.Without it a similar procedure produces only surface adhesion betweenthe film and the card and the bond is unsatisfactory for practicalpurposes. Increasing the amount of heating in an effort to producegreater fluidity and perhaps better bonding merely results in heatdarnage to the card and/or the film as already described.

One embodiment of the invention has been illustrated in the accompanyingdrawings and described with particularlity in the following description,but it is to be understood that the invention is not restricted to this1 embodiment but is capable of various mechanical and a physical forms,so that the drawings are not to be construed as a definition of theinvention, reference being had to the appended claims for this purpose.

In said drawings, FIG. 1 is a partial illustration of an apertured cardof the well known IBM type, having a transparency such as a section ofmicrofilm mounted in an aperture therein.

FIG. 2 illustrates a suitable blank card impregnated in strip patternoutlining two apertures for eventual mounting of two difierenttransparencies, and also indicating in dot and dash lines possiblevariations in the size, number and location of apertures that might bedesired under dilferent conditions;

FIG. 3 illustrates diagrammatically a suitable method of applying theimpregnating liquid to the cards;

FIG. 4 is a diagrammatic perspective view of a suitable type ofapplicator device to be used as shown in FIG. 3;

FIG. 5 is a section on the line 55 of FIG. 2, showing the impregnationof the card;

FIG. 6 illustrates diagrammatically the operation of die-cutting theaperture in the card;

FIG. 7 is a perspective view illustrating the operation of applyingmicrofilm section to the aperture preparatory to bonding;

FIGS. 8 and 9 illustrate successive stages in the bonding operation,using resistance heating;

FIG. 10 is an enlarged detail sectional view showing the resulting bond;and

FIG. 11 shows diagrammatically the presently pre ferred method of makingthe card shown in FIG. 10 by dielectric heating or so-called electronicwelding.

The card shown in FIG. 1 is a punch card of known type currently in usewith machine sorting equipment and bears on its face vertical columns ofnumerals from zero to nine, the number of such columns being as many as75-80. As will be understood by those skilled in this art, each numeralrepresents a location which can be punched according to a pre-arrangedcode so that the cards can thereafter be sorted mechanically by deviceswhich sense the locations of the punched-out openings.

Located at any suitable point in the card 1 is an aperture 2 of anydesired size and shape corresponding to the transparency to be mounted.The particular location of the aperture that is shown in FIG. 1 is forpurposes of illustration only and has no significance, any desiredlocation being selected according to the requirements of intended use ofthe card. Of course,.the selected location must take into account thecode punching requirements, since the area selected for the aperture cannot be used for punching in the normal manner.

The transparency 3 covers the aperture 2 and is bonded to the edges ofthe aperture throughout an overlapping area of suitable extent, asindicated by the dotted line 4. As already explained, the transparencymay be of any desired type, and for purposes of the followingdescriptionit is assumed by way of example to be a microfilm of an engineeringdrawing which can be projected by exposing the card 1 to a suitablesource of light. Any desired number of prints of any desired size canalso be made from the card before it is returned to storage.

FIG. 2 illustrates by way of example possible locations of two apertureswhich are outlined by the impregnated strip patterns 5 and 6 shown asstippled areas in the figure. The dotted lines 7 and 8 show the intendedlocations of the edges of the apertures that will eventually be cut whenthe time comes to mount microfilm sections or like transparencies in themanner shown in FIG. 1. As shown, the strip pattern 5 correspondssubstantially to the location of the single aperture shown in FIG. 1,and thus represents a blank card as it would be manufactured and sold inquantity for the eventual preparation of a series of cards of the FIG. 1type. As shown in plied preferably to back of the card, i.e., the sideopposite 8 the face on which the numerals in FIG. 1 appear. Thus thefilm section, when eventually mounted, will be applied to the back ofthe card.

The second strip pattern 6 is shown to illustrate the possibility ofmounting more than one film section in a single card, Whenever desired.It will be understood from the foregoing description that it is notnecessary to mount both cards simultaneously. For example, it may bedesired to cut out the aperture along the dotted line '7 and mount onefilm section in this aperture as shown in FIG. 1, leaving the cardintact at the location of the'strip pattern 6 until some indefinitefuture time when it may become desirable to cut out the second aperturealong the line 8. The series of dotted rectangles 9 illustrate otherpossible variations of the location, size and shape of apertures.

Referring now to FIG. 3, it is desirable for most purposes, andespecially for large quantity production, to apply the impregnatingmaterial in the desired strip pattern '7 and/or 8 by mechanical means.FIG. 3 shows diagrammatically a type of equipment that can be used forthis purpose. As indicated in this figure, blank cards 1 are fedlengthwise in succession by means of a suitable conveyor 1t? driven by aroll 11 and pass into the throat formed between a backing roll 12 and anapplicator roll 13 which are rotated simultaneously in the directionsshown by the arrows. As a card passes between the rolls 12, 13, it islinked by means of applicators 14 according to the desired pattern,these applicators being of Wick-type material and being supplied withimpregnating solution by means of a transfer roll 15 rotating in a bath16 of the solution. The printed cards pass between the rolls 12, 13 to adischarge conveyor 17 similar to the conveyor 10, 11.

FIG. 4- shows more clearly, although still diagrammatically, a suitablearrangement of the applicators 14 on the roll 13 for making strippatterns of the type shown in FIG. 2. As shown, the circumferentialbands at the ends of roll 13 will apply the horizontal strips of therectangular stippled patterns 5 and 6 of FIG. 2 while the axial strips18 will apply the vertical strips. It will be, evident that by suchmeans, blank cards such as illustrated in FIG. 2 can be produced veryrapidly and in large quantities at low cost.

FIG. 5 is a section taken on the line 55 of FIG. 2 for the purpose ofillustrating the effect of the printing operation shown in FIG. 3. Thestippled area 19 of FIG. 5 shows the impregnation of the card 1 to asuitable depth by the solution from the bath 16, the solvent evaporatingrapidly after impregnation and depositing the desired impregnant such ascellulose acetate in the fibers of the card. The dotted line 20 in FIG.5 corresponds to the dotted line 7 in FIG. 2, these lines being shown inboth cases merely to illustrate where the cut will eventually be made toform the aperture.

The operation of cutting out the aperture can be performed by hand asalready stated, but ordinarily will be performed by means of a suitablecutting or punching die as illustrated diagrammatically in FIG. 6. Inthis case the card 1 is shown lying on a bed plate 21 in which the dieopening 22 is formed. The die member 23 has its end 24 suitable shapedto co-operate with the die opening 22 and to cut out a section of thecard 1 predetermined along lines such as the dotted line 7 of FIG. 2,thus forming the desired aperture. In some cases it may be desired toprovide a loose fit of the die member 24 in the die opening 22, asindicated by the location of the arrows 25, with the result that theedges of the aperture will be torn somewhat roughly rather than cutsmoothly and evenly. In some cases such rough edges appear to improvethe bonding action, but they are not necessary to obtain a bond that isfully satisfactory for most purposes.

FIGS. 7, 8 and 9 illustrate the subsequent operation of mounting atransparency in the aperture cut out by the die mechanism of FIG. 6; Byway of example, a

areas-ts section of. microfilm has been illustrated in these figures,this film comprising the usual base 26 of cellulose acetate coated onone side by a light-sensitive emulsion 27. The film section is placedagainst the back of the card with the base 26 next to the card andtheemulsion coating 27 facing outwardly. The cellulose acetate base 26overlapping the impregnated edges 19 of the aperture. The extent .of'theoverlap can vary as desired. For most purposes, using cellulose acetateas an impregnant and microfilm as a transparency, an overlap from to issufficient to provide a satisfactory bond, but more overlap can be usedif desired.

With the card and film in the relative positions shown in FIG. 7, thebonding operation can be performed as shown in FIGS. 8 and 9 by means ofpressure applied by a suitable ram 28 and heat supplied simultaneouslyby a suitable metallic distributing plate 29 and heating coils 30. Asshown in FIG. 8, the area of application of pressure by the ham head 28is sufiicient to cover the area of overlap of the film and card at theedges of the aperture. The application of heat is also restrictedsubstantially to this area by means of the distributing plate 29,

the size and shape of which corresponds substantially with the ram head.

FIG. 9 shows the bonding operation in which the ram head has beenlowered to apply pressure to and to squeeze together the card and filmover their overlapping areas, while simultaneously applying heat tothese areas by means of the coils 30. The temperature to which the basematerial of the film and the impregnant in the card are heated should berestricted to the point at which these materials become sufiicientlysoft and plastic to merge or fuse together under the applied pressure,since fuuther heating to a point at which they might be more fluid wouldinvolve the risk of damaging the film and the card as already explainedabove. Using Nichrome coils 30 and a pressure of the order of severalhundred pounds (i.e. total pressure on the ram 28), it has been foundthat the desired temperature can readily be attained in a brief periodof the order of -10 seconds of energization of the heating coils. In thecase of cellulose acetate, for example, the softening point varies fromabout 6097 C. whereas the actual melting point is about 260 C. Suchhigher temperatures are unnecessary since the softening of the celluloseacetate, together with the application of pressure produces the-desiredre sult as explained below. i

Referring to FIG; 10, the edges of the card 1 surrounding the apertureare depressed somewhat by the pressure applied through the ram 28,together withthe heating effects, as indicated at 31. By way of example,a card 1 of the type illustrated in FIG. 1 mayhave an initial thicknessof the order of 0.007 inch and may be compressed at the edge of theaperture to a thickness of the order of 0.005 to 0.006 inch dependingupon the amount of heat utilized and the amountof pressure applied. Onthe other hand, the microfilrn zd, 27 may have an initial thickness ofthe order of 0.0055 inch, a major portion of which is the celluloseacetate base 26. Under the effect of heat, the base 26 softensandbecornes thermoplastic so that the pressure not only compresses theedge of the card as already explained, but also tends to squeeze atleast part of the sofitened base material of the film itself out of thejoint between the overlapping surfaces of the fihn and the card. Thusthe actual thickness of the over-,

lapping edge portion 32 of the film is also reduced substantially asindicated in FIG. 10,'sincea substantial part of the cellulose acetatebasehas been squeezed out laterally as indicated at 33, or inwardlyaround the edges of the aperture at 34. The combined thickness of thecompressed edge of the card and the overlapping edge 32 of the film isnot materially greater than the original thickness of the card 1 alone.This is possible because the major thickness of the film sectionthroughout the area of the aperture is depressed into the aperture asshown in FIG. 10, leaving a substantially flush upper surface.

The bonding action results from the fact that the softened celluloseacetate from the film base 26 and the softened cellulose acetate of theimpregnated zone 19 in the card are squeezed together under pressure andmerge or coalesce into a homogeneous integral mass of material in whichat least the surface fibers of the card are embedded. It is notnecessary to force the softened base material of the film into the cardfibers so as to effect impregnation. This would be difficult if notimpossible to achieve because of the dense compact texture of the carditself, especially since the base material of the film cannot be heatedto a high temperature so as to obtain greater fluidity without the riskof serious heat damage to the card and/or the film. Since zone 19 isalready impregnated with cellulose acetate, however, it is only necessary to bring the, contacting masses of cellulose acetate to asufiiciently softened state that they will coalesce under moderatepressure in order to obtain the desired bond.

It will be seen that the thickened portion of the film section abuts theedge of the aperture along the line 3-;

1 of FIG. 10. Because of the way in which the film and card have beenprocessed, there will ordinarily be a close abutment with a tight fitol' the film section inside the aperture. It will be understood that insome cases, more complete'impregnation of the card and/ or somewhatgreater degree of squeezing-out action of the applied pressure may causeadditional bonding to take place between the abutting faces 34 of thefilm base and of the card aperture, but for most purposes this is notnecessary.

While good results have been obtained by bonding as V illustrated inFIGS. 8 and 9, it is preferable in many cases to use dielectric heatingas is shown diagrammatically in FIG. 11 but not claimed per se herein.The card and film section in this figure occupy the same relativepositions as shown in FIGS. 7, 8 and 9 described above and areinterposed between a base electrode 35 and an upper electrode 36connected by means of leads 37 to a suitable high frequency oscillator38. The dielectric heating effect is restricted to the overlapping edgesof the card and film by forming an aperture in the upper electrode E6,

the edges 38 of which parallel the edges of the aperture in the carditself and by restricting the outer edges of said upper electrode to thedesired amount of overlap. Preferably the aperture in the electrode 35is filled with a suitable plastic material ll) to hold the film fiatwhile the bonding action is taking place. Pressure is also applied, asindicatedby the arrows 41.

With such dielectric heating equipment, it is possible to concentratethe heating effect in the cellulose acetate itself, and to minimizeheating of the card because of such concentration and also because ofthe fact that the time required to heat the cellulose acetate to thedesired softening point is much less than even the few seconds requiredin the operation shown in FIGS. 8 and 9. By way of example, using atotal pressure on the upper electrode .the bond between the card andfilm is strong and permanent. 'The bonding operation can be performed atany time, regardless of the age or" the blank impregnated card, and atno time either before or after mounting the transparency is there even atrace of adhesiveness or stickiness. These features of the inventionresult in the advantages set forth in detail above.

It will be understood that the invention is not restricted to thedetails of the foregoing description or of the drawings, which have beenset forth only by way of example and can be varied by those skilled inthe art without departing from the spirit of the invention. Reference 1i should be had to the appended claims for a definition of the limits ofthe invention.

What is claimed is:

1. In record cards of fibrous material intended to be aperturedsubsequently at predetermined locations of areas of given size and shapesuitable for mounting sections of microfilm and like projectabletransparencies, a card having a continuous uninterrupted fibrous cardstructure throughout and surrounding one of said areas, a portion ofsaid uninterrupted fibrous structure con taining heat-sensitivepotentially adhesive material im pregnated therein and distributedbetween and around the fibers of said structure beneath one surface ofsaid card, said impregnating material being non-sticky at normaltemperature but heat-softenable to adhere to and hold the section to bemounted, said material being an ranged in a pattern of stripssurrounding and outlining the aperture subsequently to be formed in saidcard.

2. A record card as defined in claim 1, said impregnat ing materialcomprising cellulose acetate impregnating the fibrous material of thecard throughout a major portion of its thickness from the side of thecard on which said section is to be mounted, whereby said aperture iscut through and exposes said impregnated fibrous material.

References Cited in the file of this patent V UNITED STATES PATENTS2,294,159

1. IN RECORD CARDS OF FIBROUS MATERIAL INTENDED TO BE APERTUREDSUBSEQUENTLY AT PREDETERMINED LOCATION OF AREAS OF GIVEN SIZE AND SHAPESUITABLE FOR MOUNTING SECTIONS OF MICROFILM AND LIKE PROJECTABLETRANSPARENCIES, A CARD HAVING A CONTINUOUS UNINTERRUPTED FIBROUS CARDSTRUCTURE THROUGHOUT AND SURROUNDING ONE OF SAID AREAS, A PORTION OFSAID UNINTERRUPTED FIBROUS STRUCTURE CONTAINING HEAT-SENSITIVEPOTENTIALLY ADHESIVE MATERIAL IMPREGNATED THEREIN AND DISTRIBUTEDBETWEEN AND AROUND THE FIBERS OF SAID STRUCTURE BENEATH ONE SURFACE OFSAID CARD, SAID IMPREGNATING MATERIAL BEING NON-STICKY AT NORMALTEMPERATURE BUT HEAT-SOFTENABLE TO ADHERE TO AND HOLD THE SECTION TO BEMOUNTED, SAID MATERIAL BEING ARRANGED IN A PATTERN OF STRIPS SURROUNDINGAND OUTLINING THE APERTURE SUBSEQUENTLY TO BE FORMED IN SAID CARD.